Plasticized sulfur compositions



United States Patent "ice 3,434,852 PLASTICIZED SULFUR COMPOSITIONS Rector P. Louthan, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware No Drawing. Filed Sept. 20, 1965, Ser. No. 488,723 Int. Cl. C09k 1/00; C09d 5/00 US. Cl. 106-49 9 Claims ABSTRACT OF THE DISCLOSURE Plasticizer sulfur compositions possessing desirable properties are produced by the reaction of 3 to 30 parts by weight of a polythiol per 100 parts by weight of sul fur. In addition sulfur based marking compositions possessing a high degree of whiteness and having good impact strength are prepared by the use of a white extender pigment and a halogenated polyphenyl in conjunction with the plasticized sulfur.

This invention relates to plasticized sulfur compositions. In one aspect of this invention relates to novel compositions containing plasticized sulfur.

In a further aspect this invention relates to novel compositions of plasticized sulfur which are suitable for use as road-marker materials.

Unmodified elemental sulfur is known to be moldable, but the low tensile strength and brittleness of the resulting product render it unsuitable for many purposes. Thus many plasticized sulfur compositions have been prepared in an effort to modify the elemental sulfur, but often the sulfur becomes chemically incorporated into the organic polymer produced. It is highly desirable of modified sulfur compositions to possess a high tensile strength and a high hardness while containing a portion of the sulfur in an elemental form.

In addition, compositions containing plasticized sulfur have been proposed for use as road-marker materials. However, such compositions are yellow unless suitably pigmented. The production of white, or nearly white, plasticized sulfur compositions requires that some substance be added to mask the natural yellow color. Furthermore, if the whitened composition is used as a marking composition, e.g., in the marking of highways, streets, roads, airport landing strips, and the like, it is important that the mark produced be of sufficiently high impact strength.

It is thus an object of this invention to provide novel compositions of plasticized sulfur.

Another object of this invention is to provide a plasticized sulfur composition of increased tensile strength wherein a major portion of the sulfur remains in the elemental form.

A still further object of this invention is to provide a plasticized sulfur marking composition having a combination of desired whiteness and impact strength.

Other aspects, objects and the several advantages of this invention are apparent from a study of the disclosure and the appended claims.

In accordance with my invention, plasticized sulfur compositions possessing desirable properties are produced by the reaction of certain polythiols with elemental sulfur in the presence of a basic catalyst. Applicable polythiols are those having the formula Y(SH),,, where n is an integer selected from the group consisting of 2, 3, and 4, preferably 2 or 3, and Y is a radical having a valence of n and containing 2-30, preferably 240, carbon atoms, each of said carbon atoms preferably having attached thereto not more than one SH group, said radical Y being selected from the group consisting of (A) radicals containing carbon and hydrogen only, (B) radicals containing carbon,

Patented Mar. 25, 1969 hydrogen, and oxygen only, and (C) radicals containing carbon, hydrogen, and sulfur only, the sulfur being present as monosulfide linkages. Radicals containing carbon and hydrogen only include saturated aliphatic, unsaturated aliphatic, saturated cycloaliphatic, unsaturated cycloaliphatic, and aromatic radicals, and combinations thereof. Radicals containing carbon, hydrogen, and oxygen only include saturated aliphatic, unsaturated aliphatic, saturated cycloaliphatic, and unsaturated cycloaliphatic radicals and aromatic radicals, and combinations thereof, possessing hydroxy, ester, aldehydic, or ketonic substituents, or ether linkages, the total number of said substituents and linkages preferably not exceeding two. Radicals containing carbon, hydrogen, and sulfur only, the sulfur being present as sulfide linkages, include saturated and unsaturated hydrycarbyl radicals in which one or more methylene groups not adjacent to the thiol groups in the molecule are replaced by monosulfide linkages, said monosulfide linkages being separated by at least one carbon atom when more than one monosulfide linkage is present, and the number of said monosulfide linkages preferably not exceeding 10. Such compositions are distinguishable over those heretofore known in the art in that the polythiol is free from polysulfide linkages and the major portion of the sulfur remains in element-a1 form rather than being chemically bonded within the organic polymer molecule.

Further, in accordance with my invention, the plasticized sulfur compositions of this invention possess even more desirable properties if prepared through use of a trithiol or tetrathiol, preferably a trithiol, in combination with a dithiol. The use of a mixture of a dithiol and a trithiol or tetrathiol results in plasticized sulfur compositions whose properties are quite different than would be expected on the basis of the properties of compositions prepared through use of the polythiols individually.

I have further discovered that sulfur-based marking compositions possessing a high degree of whiteness and having good impact strength are prepared by the use of a white extender pigment and a halogenated polyphenyl in conjunction with sulfur plasticized with at least one dithiol selected from the group consisting of S-(Z-mercaptoethyl)cyclohexanethiol and 4-(Z-mercaptoethyl)cyclohexanethiol. The white extender pigment whitens the plasticized sulfur, which already is substantially whiter than elemental sulfur or sulfur plasticized with polythiols generally, and imparts higher impact strength to the plasticized composition. The halogenated polyphenyl serves to decrease the viscosity of the molten composition to a level suitable for direct application as a spray. The dithiols named above as plasticizers are unique in making possible the production of marking compositions of high impact strength which are whiter than those produced in a similar manner when other polythiols are used in the plasticization.

Examples of some polythiols that can be used in the preparation of the compositions of one aspect of this invention are those selected from the group consisting of 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,2,3-propanetrithiol, 1,2-butanedithiol, 2-methyl-1,2-propanedithiol, 1,4-butanedithiol, 1,2,4-butanetrithiol, 1,2,3,4-butanetetrathiol, 1,2,3-pentanetrithiol, 1,6-hexanedithiol,

3 -methyl-2,3-heptanedithiol, 1,2,10-decanetrithiol, 2-methyl-1,14-tetradecanedithiol,

1,20-eicosanedithiol,

1,3 O-triacontanedithiol,

3-butene-1,2-dithiol,

2butene- 1,4-dithio1,

2-methyl-3-hexene-1,2,5,6-tetrathiol,

3,6-octadiene-1,2,8-trithiol,

3-hexyne-'1,6-dithjol,

1,2-cyclohexanedithiol,

3- (Z-mercaptoethyl cyclohexanethiol,

4-methyl-1,2,3-cyclopentanetrithiol,

1-cyclopentyl-1,Z-ethanedithiol,

4-cyclohexene-1,2-dithiol,

2,5 -cyclohexadiene- 1,4-dithiol,

S-cyclooctyne-1,2-dithiol,

4-methy1-3-cyclopentene-1,2-dithiol,

1,4-benzenedithiol,

1,2,4-b enzenethrithiol,

1,2,4,5-benzenetetrathiol,

toluene-2,4-dithiol,

toluene-w4-dithiol,

1,4-naphthalenedithiol,

4-hydroxy-1,2,3-butanetrithiol,

3-acetoxy-1,2-propanedithiol,

2-formyl-1,Z-ethanethiol,

3-acetyl-1,2-pr0panedithiol,

bis Z-mercaptoethyl) ether,

bis 3-mercaptropropyl ether,

l,2-bis,2-mercaptoethoxy ethane,

2,3-dihydroxy-1,4-butanedithiol,

1,4-dimethoxy-2,3-butanediti1iol,

5-hydroxy-3-pentene-1,Z-dithiol,

6-propionyloxy-3-hexene-1,2-dithiol,

4-formy1-3-butene-1,Z-dithiol,

4-propionyl-3-butene1,Z-dithiol,

bis 3-mercaptopropenyl ether,

3-hydroxy-4-cyclohexene-1,2-dithiol,

4-methyl-5-acetoxy-3-cyclopentene-1,Z-dithiol,

6-formyl-2-cyclohexene-1,4-dithiol,

5-acetyl-3-cyclohexene-1,2-dithiol,

bis (-4-mercapto-2 cyclopenten- 1 -yl ether,

3-hydroxy-1,2-benzenedithiol,

5 -acetoxy-1 ,2,4-benzenetrithiol,

4-formyl-1,2-benzenedithiol,

Z-acetyl-1,4-benzenedithiol,

4-ethoxy-1,2-benzenedithiol,

4,5 -dihydroxy- 1 ,Z-benzenedithiol,

Z-methoxy-S -acety1- l ,4-b enzenedithiol,

bis Z-mercaptoethyl) sul-fide,

bis( 3-mercaptopropyl sulfide,

2-mercaptoethyl-2,3-dimercaptopropyl sulfide,

bis (2,3-dimercaptopropyl sulfide,

4-mercaptobutyl-S-mercaptopentyl sulfide,

3,5 -dithiaheptane-1 ,7-dithiol,

3,6,-9-trithiaundecane-1, 1 l-dithiol,

4,-8,l2,l6-tetrathianonadecane-1,1'9-dithiol,

5,10,15,20-tetrathiatetracosane-1,24-dithiol,

3,6,9,12,15,18,21,24,27,3 0-decathiadotriacontane- 1,32-dithiol,

4, 8, 12, 16,20,24,28,3 2,3 6-nonathianonatriacontane- 1,39-dithiol,

bis 4-mercapto-2-butenyl sulfide,

Z-mercaptoethyl 4-mercaptocyclohexyl sulfide,

bis 3-mercaptocyclopentyl sulfide,

bis (4-mercapto-2-cyclohexen-1-yl) sulfide,

bis 4-mercaptophenyl sulfide,

bis(2-mercapto-p-tolyl) sulfide, and

1,4-bis (4-mercaptophenylthio benzene.

Any basic catalyst can be employed in the preparation of the plasticized compositions of this invention. The preferred catalysts are amines, ammonia, and the oxides, hydroxides, and carbonates of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium. The amines can be primary, secondary, or tertiary, and they can contain saturated or unsaturated aliphatic or cycloaliphatic groups or aromatic groups, or

combinations thereof, in the molecule. Heterocyclic amines are included among the applicable amines. The amines most generally perferred are the saturated aliphatic amines having 320 carbon atoms. Some examples of amines of this type are propylamine, trimethylamine, N-methylethylamine, isobutylamine, hexylamine, octylamine, diphenylamine, triproplamine, tributylamine, diheptylamine, and N,N,-dihexy1octylamine. Amines and ammonia are particularly useful catalysts when a rapid reaction between the polythiol and sulfur is desired. On the other hand, calcium carbonate is a cheap and especially useful catalyst when it is desirable or necessary that the composition be maintained at an elevated temperature for a prolonged period of time.

In the preparation of the compositions of this invention, the ratio of polythiol to sulfur will usually be in the range of 330 parts by weight of polythiol to 1 00 parts by weight of sulfur, preferably in the range of 520 parts by weight of polythiol to 1 00 parts by weight of sulfur. The concentration of basic catalyst is not critical, but the catalyst is perferably employed in an amount equivalent to 0.01-5 parts by Weight per parts by weight of sulfur.

Although any of the polythiols can be used in combination, it is often especially advantageous, as mentioned above, to employ both a dithiol and a trithiol or tetrathiol in the preparation of the plasticized sulfur compositions. The dithiol and trior tetrathiol can be employed over a wide range of ratios; however, the ratio of dithiol to trior tetrathiol should usually be in the range of 1:9 to 9:1, and will most often be in the range of 1:4 to 4: 1, depending on the nature of the polythiols and on the properties desired in the plasticized sulfur compositions.

Although the plasticized sulfur compositions are preferably prepared in the absence of added solvent, suitable solvents such as chloroform, carbon tetrachloride, benzene, toluene, and xylene can be used. The reaction temperature is generally maintained within the range of about 20 to 250 0., preferably within the range of about 20 to 200 C. The reaction period varies, depending on the temperature and on the nature and concentration of the components in the reaction system, but should be in the range of about 1 minute to about 2 days, usually being within the range of about 3 mintues to about 4 hours. The pressure need be only sufficient to maintain the polythiols and solvent, if used, substantially in the liquid phase. Hydrogen sulfide, which is evolved during the reaction, can be removed as it is formed. If a solvent is used, the solvent can be removed by volatilization upon completion of the reaction.

The compositions of this invention can be readily molded or cast to give materials which, in general, possess higher tensile strength and lower hardness than do those obtained from sulfur alone, thus fulfilling certain requirements not met by sulfur in an unmodified form. For example, the compositions of this invention can be used in the building industry as coatings and binders for strengthening and weatherproofing Walls made of concrete blocks or other building materials. The compositions can also be mixed with appropriate aggregates, or blended with asphalt, for use as a highway surfacing material. As the compositions have good impact strength, they are especially useful as highway marking paints, the com positions being applied in molten form to give a mark which quickly hardens and provides long service. The compositions, of course, can also be used in paints designed for other purposes.

To increase the tensile and impact strength of the compositions of this invention, reinforcing agents such as fibers of glass, metal, or other material can be incorporated into the compositions.

As stated above, plasticization of the sulfur to form the marking compositions of one aspect of this invention is carried out through the use of 3-(2-mercaptoethyl)- cyclohexanethiol or 4-(2-mercaptoethyl)cyclohexanethiol,

used singly or in combination. These dithiols can be readily prepared, e.g., by the method disclosed in U.S. 3,050,452. Furthermore, it is not necessary to remove higher-boiling substances, e.g., sulfides, that are normally present, as the crude mixture of isomeric dithiols contaminated with higher-boiling substances is quite suitable, thus permitting the plasticizer to be obtained at low cost.

Preferably, the sulfur is first plasticized, and the white extender pigment and halogenated polyphenyl are then added, either at the same time or either one followed by the other. Thorough mixing of the extender pigment and halogenated polyphenyl with the plasticized sulfur is readily achieved by stirring at a temperature at which the plasticized sulfur is molten. Less preferably, the pigment and/or halogenated polyphenyl can be added to the sulfur and/or to the plasticizer prior to plasticization of the sulfur.

White extender pigments suitable for use in this aspect of the invention are those pigments selected from the group consisting of calcium carbonate, calcium sulfate, magnesium silicate, magnesium carbonate, magnesium oxide, china clay, pyrophlyllite, mica, pumice, bentonite, silica, diatomite, barium sulfate, barium carbonate, alumina hydrate, and calcium silicate.

Halogenated polyphenyls which can be used in the process of this invention include halogenated biphenyl, halogenated o-terphenyl, halogenated m-terphenyl, and halogenated p-terphenyl. Mixtures of these halogenated polyphenyls, of course, can be used. The halogenated biphenyl can have l-lO halogen atoms per molecule, and each of the halogenated terphenyls can have 1-14 halogen atoms per molecule. Although the halogen in the halogenated biphenyl and halogenated terphenyls can be fluorine, chlorine, bromine, or iodine, it is preferable that the halogen be chlorine. Particularly useful halogenated biphenyl and halogenated terphenyls are the chlorinated biphenyl and chlorinated terphenyls (Aroclors) available from Monsanto Co.

Unexpectedly, plasticization of sulfur by the mercaptoethylcyclohexanethiols used in this invention requires no catalyst. However, basic catalysts such as amines, ammonia, and the oxides, hydroxides, and carbonates of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium can be used, e.g., in amounts up to about 5 weight percent of the sulfur employed, if an accelerated reaction is desired. Although solvents such as chloroform, carbon tetrachloride, benzene, toluene, and xylene can be present during the plasticization, it is preferred that they not be used.

The ratio of mercaptoethylcyclohexanethiols to sulfur can vary within a broad range, but will usually be within the range of about 3-30 parts by weight of dithiol to 100 parts by weight of sulfur, preferably within the range of about 5-20 parts by weight of dithiol to 100 parts by weight of sulfur. The temperature at which the plasticizetion is carried out is generally maintained within the range of about 50250 C., preferably within the range of about 100200 C. The time required for the plasticization varies depending on the temperature and on the nature and concentration of the components in the systern, but should be within the range of about 5 minutes to about 2 days, usually being within the range of about minutes to about 6 hours.

As stated above, the white extender pigment and halogenated polyphenyl are preferably added to the plasticized sulfur, rnixing being achieved by stirring or otherwise agitating the pigmented molten mixture. The ratio of pigment to plasticized sulfur should be within the range of about 150 parts by weight of pigment to 100 parts by Weight of plasticized sulfur, preferably being within the range of about 3-20 parts by weight of pigment to 100 parts by weight of plasticized sulfur. The ratio of halogenated polyphenyl to plasticized sulfur should be within the range of about 1-50 parts by weight of halogenated polyphenyl to 100 parts by weight of plasticized sulfur,

preferably being within the range of about 3-20 parts by weight of halogenated polyphenyl to 100 parts by weight of plasticized sulfur. In general, the use of equal amounts, by weight, of pigment and halogenated polyphenyl gives a suitable product.

The sulfur-based marking compositions of this invention are of suflicient whiteness and impact strength to make them ideally suitable as white marking compositions, e.g., in the marking of highways, streets, roads, airport landing strips, and the like. Of course, other materials such as sand, glass beads, and the like can be added to impart special properties sometimes desired in marking compositions.

The following examples are presented to further illustrate the invention.

EXAMPLE I A series of plasticized sulfur compositions was prepared by adding 4, 10, 15, or 20 parts by weight of a polythiol containing 0.1 part by weight of tributylamine to 100 parts by weight of molten sulfur at 135 C. over a period of about 5 minutes, during which time hydrogen sulfide was liberated from the mixtures. The mixtures were maintained at about 135 C, for an additional 15 minutes and then compression molded at 24,000 p.s.i. and about 100 C., in a Carver press, into 4% in. x /2 in. x /s in. test bars. The tensile strength of the test bars was determined with an Instron tensile machine, utilizing a gauge length of 2 in. and a pulling rate of 0.2 in./min. The Shore D hardness was determined with a Shore durometer. The results of these tests, together with those of similar tests made on bars molded from sulfur alone, are shown in Table I.

TABLE I Polythioll, Tensile Shore Polythiol Reactant Parts per 100 Strength, D" Parts Sulfur, p.s.i. Hardby Weight ness a 65 1,2-ethaned1th1 420 66 0 310 55 1,2-pr0panedithiol 200 68 Do 142 62 Do 15 303 58 Do 20 239 49 1,2,3-propanetr1thiol 10 730 1,6-hexanedithi0l 10 41 (3 or 4) (2- ercaptoethyl) cyclohexanethiol b 10 109 67 B1s(3-rnercaptopropyl) ether 10 88 41 Polytliiaalkane-a,w-dithiols 10 234 u ASIM D1706-6L Shore durometer, type D.

b Prepared by the method of Example I in U.S. 3,050,452.

a A mixture of 331.5 g. of 3-chloro-1-propanctlii0l, 360 g. of sodium sulfide nonahydrate, g. of sodium hydroxide, and 1,257 1111. of water was stirred in an autoclave at C. for 30 minutes. The reaction product was acidified with 300 ml. of concentrated hydrochloric acid and then extracted with benzene. The benzene extract was washed with water, after which the benzene was distilled. The residue was then heated to 250 C. at less than 1111111., leaving in the distillation flask a mixture of crude polythiaalkane mwdithiols having an average molecular Weight of 545 and a mereaptan sulfur content of 10.3 Weight percent. This mixture of crude dithiols was used without further purification.

Thus, plasticization of the sulfur by the action of polythiols in the presence of a catalytic amount of tributylamine gave compositions which on molding were generally of higher tensile strength and lower hardness than was molded sulfur alone.

EXAMPLE II Another series of plasticized sulfur compositions was prepared by adding 10 parts by weight of a polythiol, at one time, to a molten slurry of 2.5 parts by weight of calcium carbonate in 100 parts by weight of sulfur at C., at which temperature the mixtures were maintained for 30 minutes. Hydrogen sulfide was liberated during this reaction period. The reaction mixtures were then molded into test bars, as in Example I, and the tensile strength and hardness were determined as described in Example I. The results of these tests, together with those of similar tests made on bars molded from sulfur alone, are shown in Table II.

ASTM D1706-61. Shore durometei', type D.

Thus, plasticization of the sulfur by the action of polythiols in the presence of a catalytic amount of calcium carbonate gave compositions which on molding were generally of higher tensile strength and lower hardness than was molded sulfur alone.

EXAMPLE III A series of plasticized sulfur compositions was prepared by adding 10 parts by weight of various mixtures of 1,2-ethanedithiol and 1,2,3-propanetrithiol containing 0.1 part by weight of tributylamine to 100 parts by weight of molten sulfur at 135 C. over a period of about 5 minutes. Hydrogen sulfide was liberated during the addition. The mixtures were maintained at about 135 C. for an additional 15 minutes and then molded into test bars, as in Example I. The tensile strength and hardness of the test bars were determined as described in Example I. The results of these tests are shown in Table III. For comparison purposes there are included the tensile strength and hardness of test bars prepared in the same manner as those above except that parts by weight of the dithiol or 10 parts by weight of the trithiol was substituted for the 10 parts by weight of the mixture of dithiol and trithiol.

TABLE III [Basisz 100 parts sulfur; 0.1 part tributylamine] B ASTM 131706-61. Shore durometer, type D.

Thus, the tensile strength of the compositions prepared through use of mixtures of the dithiol and trithiol was much higher than would have been expected on the basis of the tensile strength of the compositions prepared through use of each polythiol individually, and the hard ness remained at an acceptable level.

Into a plasticized composition the same as that having a tensile strength of 1390 p.s.i., as shown in Table III, was incorporated 3.5 parts of 0.5-in. standard reinforcing glass fibers per 100 parts of sulfur used in preparing the plasticized composition. The resulting reinforced plasticized composition had a tensile strength of 2975 psi EXAMPLE IV A series of plasticized sulfur compositions was pre pared by adding a mixture of 5 parts by weight of a 8 dithiol, 5 parts by weight of 1,2,3-propanetrithiol, and 0.1 part by weight of tributylamine to parts by weight of molten sulfur at C. over a period of about 5 minutes, during which time hydrogen sulfide was liberated from the mixtures. The mixtures were maintained at about 135 C. for an additional 15 minutes and then molded into test bars, as in Example I. The tensile strength and hardness of the test bars were determined as described in Example I. The results of these tests are shown in Table IV. For purposes of comparison there are included the tensile strength and hardness of test bars prepared in the same manner as those above except that 10 parts by weight of the dithiol was substituted for the mixture of 5 parts by weight of dithiol and 5 parts by weight of 1,2,3-propanetrithiol. When 10 parts by weight of 1,2,3- propanetrithiol was substituted for the mixture of 5 parts by weight of the dithiol and 5 parts by weight of the trithiol, the tensile strength and Shore D hardness of the molded test bars were 730 psi. and 90, respectively.

TABLE IV With Without Propanetrithiol Propanetrithiol Dithiol Component Tensile Shore Tensile Shore Strength, D Strength, D p.s.i. Hardp.s.i. Hardness ness I1 1 ,2-propanedithi0l 620 80 142 62 1,6-hexanedithiol 379 78 41 3 (and 4) 1 (Z-mercaptoethyl) cyelohexanethiol 895 82 109 67 Bis (3-mercaptopropyl) ether 370 78 88 41 u ASTM D1706-61. Shore durometer, Type D.

EXAMPLE V In a series of experiments 922.6-930 g. of sulfur and 5.0 g. of calcium carbonate were dry-blended for a few minutes in a Readco blender, after which a liquid dithiol was added to each of the blends over a period of about 5 minutes. The mixtures were then blended for an additional period of about 25 minutes. As pigmented sulfur compositions plasticized with a combination of an aliphatic polysulfide and a styrene polysulfide have been reported to be effective highway marking material, a control experiment was carried out in which 895 g. of sulfur, 50 g. of styrene polysulfide, and 5.0 g. of calcium carbonate were dry-blended for a few minutes in a Readco blender, after which 50 g. of aliphatic polysulfide (a liquid) was added to the blend over a period of about 5 minutes. The mixture was then blended for an additional period of about 25 minutes. With 1,2-ethanedithiol, or 1,2-propanedithiol as the plasticizer, there was vigorous evolution of hydrogen sulfide during blending. However, with the combination of an aliphatic polysulfide and a syrene polysulfide, as the plasticizer, only a small amount of hydrogen 9 10 sulfide was liberated. After standing at least 18 hours at cized sulfur composition prepared above prior to the inroom temperature, each Sample was heated in an oil bath coropraton of the Celite and Aroclor substances, each a C- f 2 hows: At the end f heatiPg periofl sample being cast in the manner described above. The the Samples were Cast Portlons m alummum 011 results, summarized in the following table, show that the figg f gg gg gg g' gz 223223 ii gi gzfg: 5 compositions containing the Celite and Aroclor substances ture, h Shore hardness color, and impact strength have much greater impact strength and whiteness than do were determined. The results are summarized in Table V. the controls, the hardness remaining at a suitable level.

TABLE v Wei ht of Weight of Shore B Munsell Impact Plasticizer Plasti izer, g. Sulfur, g. Hardness Color b Strength, 1n.

Aliphatic polysulfide and styrene polysulfidenu 100 895 90 11 1,2ethanedithiol 100 929 88 18 D0. 50 930 93 9 1,2-propanedithiol 100 922. 6 91 13 ASTM D1706-61. Shore durometer, type B, The Shore Instrument and Manuiactunng 00., Inc., Bulletin R-12 (no date given). b Munsell Book of Color, Munsell Color (30., Baltimore, Md. (1929).

s Minimum height from which a 28.1 -g. steel ball had to be dropped to break the -g. sample (118C.

Comprised 50 g. of Ihiokol LP-3 and 60 g. of Thiokol ZM-BQQ.

' Purity was 90-95 percent.

Thus, the impact strength of the plasticized products Sample Aroclor Used Impact ShOIeKB" Munsen prepared through the use of 100 g. of 1,2'ethaned1th1ol or No. Strength, in. Hardness Color 100 g. of 1,2-propanedithiol was higher than that of the None 4 92 7.5Y 8/10 plasticized product obtained through the use of 100 g. of 30 L Sg g 3? i qgfwthe combination of an aliphatic polysulfide and a styrene Aroclor 33 82 lows/2' polysulfide, and 50 g. of 1,2-ethanedithiol gave a product 4 $332; 5%: i 3? igggg having an impact strength only slightly lower than that M llnurnh htf hl 28.1-.t1bllhdt b dr (1 of the product obtained through the use of 100 g. of the 35 to g the 30 gj gga a g 5 99 a a 0 8 PP b ASTM D1706-61. Shore durometer, type B. The Shore Instrument Thlokol plasticizers. The hardness of the various plastr and Manufacturing Co, Inc Bulletin B42010 date wen) cized products did not differ greatly. The C010! Of each glgli/lunseil 130011; of Cplor, Munsell Color 00., Baltimore, Md. (1929).

omen a su ur on y. of the Products was Sufliclenfly hght to permit the use of Plasticized sulfur in the absence of Celite and Aroclor. pigments i i t f r lati s h 1 Chlorinated biphenyl containing approximately 32 weight percent c orine. While the examples hBlBln 11111811 one method for 40 hi Chlorinated biphenyl containing approximately 42 weight percent C orlne. achlevmg Plastlcatlo} P the Sulfur P It IS advan Chlorinated biphenyl containing approximately 54 weight percent tageous to first plastlcrze only a portion of the sulfur, dinonne.

i Chlorinated terphenyls containing approximately 60 weight percent the remainder of the sulfur, as well as the other desired chlorinm constituents, being added subsequently.

EXAMPLE VII A plasticized composition was prepared from sulfur and crude 3(and 4) (Z-mercaptoethyl)cyclohexanethiol as in Example VI except that no calcium carbonate was employed. The resulting roduct had a viscosit of 290 P p by the Pf of Example I lcentipoises at about 165 C. A portion of this product Samp of a Plastlclzed Sulfur Composltlon were was cast in the manner described in Example VI and then pared by heating a mixture of 913.4 g. of sulfur, 10(1 g. allowed to age for 7 days The properties of the aged of crude 3(and -p y y i composition, determined as in Example VI, were as and 5 g. of calcium carbonate in an oil bath at 160170 f ll C. for 3 to 4 hours. There was vigorous evolution of hy EXAMPLE VI A crude mixture of 3 (2 mercaptoethyl)cyclohexanethiol and 4 (2 mercaptoethyl)cyclohexanethiol was I t t th, drogen sulfide during the fiISt o of the heatmg p 8 1 33; fg gg 8'? To each of a series of -g. portio f t resulting Munsen m Zip lam plasticized sulfur in an oil bath at 170' C. was

added, with stirring, 9.0 g. of Celite analytical filter aid 60 To 894 the plasticized compmiiion abme (diatomite), resulting in an increase in viscoslty of the resulting mixture was stirred for 1 hour at was added 89.4 g. of Celite analytical filter aid, and the molten plasticized Sulfur- The Pigmented plasticized $111 to give a product having a viscosity of 4800 centipoises fur was then stirred at 160-l70 C. for 15 minutes, after at about C. Then 89.4 g. of Aroclor 1254 was added, which 9.0 g. of one of several Aroclor substances (chlori- 55 and the miXtllre Was Stirr d at 160-170 C. for 1 hour,

nated polyphenyls) was added to reduce the viscosity to giving a p having a Y f 710 Centipoises at a resonable level. The resulting compositions were stirred about 165 The f i addmon of Aroclor at C for 15 minutes and then cast as 30 g 1254, followed by stirring at 160-170 C. for 1 hour, re-

portions, in the form of disc 60 mm. in diameter, by pouring into aluminum foil moisture dishes. After the cast samples had aged at room temperature for 7 days, used in Example VI. the impact strength, hardness, and color were determined.

70 about 165 C. The final product, after aging for 7 days,

Impact strength, in 28 duced the viscosity of the product to 422 centipoises at had the following properties, determined by the procedure For purposes of comparison these properties were also Shore hardness 80 determined for elemental sulfur alone and for the plasti- 75 Munsell color 2.5GY8/3 Thus, in obtaining the increased impact strength and the whitening of the product by use of the Celite and Aroclor substances, the Aroclor served the very impor tant function of reducing the viscosity of the pigmented molten composition, the hardness of the product remaining at a suitable level.

In another experiment it was observed that the addition of an Aroclor to a plasticized sulfur composition containing no Celite did not significantly whiten the product or improve its impact strength, essentially serving only to reduce the viscosity of the molten composition.

EXAMPLE VIII A plasticized sulfur composition was prepared from sulfur and crude 3(and 4)-(2-mercaptoethyl)cycloheX- anethiol as in Example VI. To 90 g. of the plasticized sulfur were added 9 g. of titanium dioxide and 9 g. of Aroclor 1254, and the resulting mixture was stirred at 160-170 C. for 30 minutes. The product was cast in the manner described in Example VI and then allowed to age for 7 days. The properties of the aged composition, determined as in Example VI, were as follows:

Impact strength, in. 16 Shore B hardness 83 Munsell color 7.5Y8.4

Thus, the impact strength was inferior to that obtained with Celite and Aroclor 1254 in Example VI, and the color was unacceptable. Therefore, titanium dioxide is not a suitable substitute for Celite in the process of this invention.

EXAMPLE IX In a 1-liter beaker equipped with a stirrer and immersed in an oil bath having a temperature of 170 C. were mixed 256 grams of sulfur and 505 grams of crude 3(and 4)-(2-n1ercaptoethyl)cyclohexanethiol. Hydrogen sulfide was evolved when the reaction solution reached a temperature of 150 C. At the end of a 4-hour reaction period essentially no more gas was being liberated. The resulting plasticized sulfur was a clear viscous liquid while hot and on cooling to room temperature became a semisolid,

To a 1-liter beaker equipped with a stirrer and immersed in an oil bath at 170 C. were charged 645 grams of sulfur and 105 grams of plasticizer (as prepared above). After being stirred for 1.5 hours, the mixture had a viscosity of 510 centipoises. The mixture Was then transferred to a heated paint sprayer having a pot temperature of 300 F. and then sprayed onto a concrete block. The material began to set in minutes and was completely set in 19 minutes. After pouring three 30- gram discs for impact strength and hardness determination, 61.7 grams of calcined pearlite was added to 617 grams of the remaining material, and the mixture was then heated with stiring at 170 C. to obtain a homogeneous mixture. The resulting mixture having a viscosity of 6800 centipoises was too viscous to spray. Chlorinated biphenyl (Aroclor 1232; 77.1 g.) was added, and the mixture thereof after stirring exhibited a viscosity of 45 0 centipoises. Upon spraying the material on concrete as above from a heated paint sprayer, initial set occurred in 0.2 minute and complete set occurred in 2.5 minutes. After seven days, the falling ball impact strength and Shore B hardness were determined. The data are summarized The above data clearly demonstrate that proceeding in accordance with this invention there is provided a suitable marking composition which has an unexpectedly short set time. Set time is important in highway marking material since it is necessary to preclude trafiic on the marked area until the marking material is set or dry. By utilizing the instant invention, the necessity of precluding traflic for a period of time is significantly reduced.

EXAMPLE X A plasticized sulfur composition was prepared by heating a mixtrue of 256 g. of sulfur and 505.2 g. of crude 3(and 4)-(2-mercaptoethyl)cyclohexanethiol at about 170 C. for 3.5 hours. Then a mixture of g. of the plasticized sulfur composition, 860 g. of sulfur, 200 g. of Icecap K (calcined aluminum silicate from Burgess Pigment Company), and g. of Aroclor 1254 was heated at l60170 C. for 1 hour. The viscosity of the resulting product was 420 centipoises at about C. After aging for 7 days, the product had the following properties, determined by the procedure used in Example VI.

Impact strength, in 18 Shore B hardness 85 Munsell color 10Y-8/3 A mixture of 70 g. of the above nonpigmented sulfur composition, 430 g. of sulfur, 100 g. of Silver Bond B (crystalline silica from Tamms Industries Company), and 50 g. of Aroclor 1254 was heated at l60170 C. for 1 hour, giving a product having a viscosity of 282 centipoises at about 160 C. After aging for 7 days, this product had the following properties, determined by the procedure used in Example VI.

Impact strength, in. 83 Shore B hardness 84 Munsell color lOY-8/3 Thus, sulfur-based marking compositions have desirable properties can be made through the use of either calcined aluminum silicate or crystalline silica, as well as through the use of diatomite.

In some cases it is advantageous to heat only a portion of the sulfur with the dithiol, dilute the resulting plasticizer with the halogenated polyphenyl, and then blend this solution with powdered sulfur and pigment to obtain the product as a dry powder.

Reasonable variations and modifications are possible within the scope of this disclosure without departing from the spirit and scope of the invention.

1 claim:

1. A plasticized sulfur composition which is formed by reacting elemental sulfur in the presence of a basic catalyst at a temperature in the range of -20 to 250 C. with from 3 to 30 parts by weight of at least one polythiol per 100 parts by weight of sulfur, said polythiol being selected from the group consisting of 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 1,2,3-propanetrithiol, 1,2-butanedithiol, 2-methy1-1,2-propanedithiol, 1,4-butanedithiol, 1,2,4-butanetrithiol,

below: 75 l,2,3,4-butanetetrathiol,

TABLE VI Sulfur, Plasticizer, Diatomite, Aroclor 1232, Viscosity, Shore B" Impact Set Time (Min) Run N0. Parts by Wt. Parts by Wt. Parts by Wt. Parts by Wt. Centipoises Hardness b Strength, Infi Start Complete Calcined pearlite. b ASTM D1706-61. Shore durometer, ty e p B. 0 Minimum height from which a 28.1 -g. steel ball had to be dropped to break the 30 -g. sample disc.

1 3 1 ,2,3 -pentanetrithiol, 1,6-hexanedithiol, 3-methyl-2,3-heptanedithiol, 1,2,10-decanetrithiol, 2-methyl-1,14-tetradecanedithiol, 1,20-eicosanedithiol, 1,3 O-triacontanedithiol, 3-butene-1,2-dithiol, 2-butene-1,4-dithiol, 2-methyl-3 -hexene- 1,2,5 ,6-te trathiol, 3 ,6-octadiene-1,2,8-trithiol, 3-hexyne-1,6-dithiol, 1 ,2-cyclohex ane dithiol, 4-( Z-mercaptoethyl) cyclohexanethiol, 3- (Z-mercaptoethyl cyclohexanethiol, 4-methyl-1,2, 3-cyclopentanetrithiol, l-cyclopentyl-1,2-ethanedithiol, 4-cyclohexene-1,2-dithiol, 2,5-cyclohexadiene-1,4-dithiol, S-cyclooctyne-1,2-dithiol, 4-methyl-3-cyclopentene'1,2-dithiol, 1,4-benzenedithiol, 1,2,4-benzenetrithiol, 1,2,4,5-benzenetetrathiol, toluene-2,4-dithiol, tluene-a-4-dithiol, 1,4-naphthalenedithio1, 4-hydroxy-1,2,3-butanetrithiol, 3-acetoxy-1,2-propanedithiol, 2-formyl-1,2 ethanedithiol, 3-acetyl-1,2-propanedithiol, bis Z-mercaptoethyl ether, bis 3-mercaptopropyl) ether, 1,2-bis( Z-mercaptoethoxy) ethane, 2,3 dihydroxy-1 ,4 butane dithiol, 1,4-dimethoxy-2,3-butanedithio1, 5-hydroxy-3-pentene-1,2-dithiol, 6-propionyloXy-3 -hexenel ,Z-dithiol, 4-formyl-3-butene-1,2-dithiol, 4-propionyl-3-butene-1,Z-dithiol, bis 3-mercaptopropenyl ether, 3-hydroxy-4-cyclohexene=l ,Z-dithiol, 4-methyl'5-acetoxy-3-cyclopentene-1,2-dithiol, 6-formyl-2-cyclohexene-1 ,4-dithiol, S-acetyl-S-cyclohexene-1,2-dithiol, bis(4-mercapto-2-cyclopenten-I-yl ether, 3-hydroxy-1,2-benzenedithiol, S-acetoxy-1,2,4-benzenetrithiol, 4-formyl-1,2-benzenedithiol, Z-acetyl-1,4-benzenedithiol, 4-ethoxy-1,2-benzenedithio1, 4,5-dihydroxy-1,2-benzenedithiol, 2-methoxy-5-acetyl-1,4 benzenedithiol, bis Z-mercaptoethyl sulfide, bis 3-mercaptopropyl sulfide, Z-mercaptoethyl-Z,3-dimercaptopropyl) sulfide, bis 2,3-dimercaptopropyl sulfide, 4-mercaptobutyl S-mercaptopentyl sulfide, 3,5-dithiaheptane-1,7-dithio1, 3,6,9-trithiaundecane-1,1l-dithiol, 4,8,12,lfi-tetrathianonadecane-1,19-dithiol, 5,10,15,20-tetrathiatetracosane-1,24-dithiol, 3,6,9,12,15,18,21,24,27,30-decathiadotriacontane-1,32-

dithiol, 4,8,12,16,20,24,28,3 2,3 6-nonathianonatriacontane1,39-

dithiol,

bis (4-m ercapto-Z-butenyl) sulfide, Z-mercaptoethyl 4-mercaptocyclohexy1 sulfide, bis 3-mereapto-cyclopentyl )sulfide, bis(4-mercapto-2-cyclohexen-1-y1) sulfide, bis(4-mercaptophenyl) sulfide,

bis(2-mercapt0-p-tolyl)sulfide, and 1,4 bis 4-mercaptopheny1thio)benzene.

2. A plasticized sulfur composition according to claim 1 wherein said polythiol comprises a mixture of a trithiol with a dithiol wherein the ratio of said dithiol to said trithiol is in the range of 1:9 to 9:1.

3. A plasticized sulfur composition according to claim 1 wherein said polythiol is composed of a mixture of a tetrathiol with a dithiol and wherein the ratio of said dithiol to said tetrathiol is in the range of 1:9 to 9: 1.

4. A plasticized sulfur composition according to claim 1 which forms on reacting elemental sulfur and ethanedithiol present in a ratio of polythiol to sulfur in the range of 3 to 30 parts by Weight of polythiol to parts by weight of sulfur at a temperature in the range of -20 to 250 C. in the presence of tributylamine.

5. A plasticized sulfur composition according to claim 1 which forms on reacting elemental sulfur and a polythiol selected from the group consisting of 1,2-ethanedithiol, 1,2-propanedithiol, 3-(2-mercaptoethyl)cyclohexanethiol, 4-(Z-mercaptoethyl)-cyclohexanethi0l and bis(3-mercaptopropyl)ether in the presence of calcium carbonate.

6. A plasticized sulfur composition according to claim 1 having high tensile strength which forms on reacting elemental sulfur with a polythiol mixture of 1,2-ethanedithiol and 1,2,3-propanetrithiol in the presence of tributylamine.

7. A sulfur-based marking composition possessing a high degree of whiteness and having good impact strength which is formed by admixing from 1 to 50 parts by weight to 100 parts by weight of plasticized sulfur a White extender pigment and from 1 to 50 parts by weight to 100 parts by weight of plasticized sulfur a halogenated polyphenyl with sulfur plasticized at a temperature Within the range of 50 to 250 C. with 3 to 30 parts by weight of dithiol to 100 parts by weight of sulfur of at least one dithiol selected from the group consisting of 3-(2-mcrcaptoethyl)cyclohexanethiol and 4-(2-mercaptoethyl) cyclohexanethiol.

8. A composition according to claim 7 wherein said halogenated polyphenyl is selected from the group consisting of halogenated bip henyl, halogenated o-terphenyl, halogenated m-terphenyl and halogenated p-terphenyl.

9. A sulfur-based marking composition according to claim 7 formed by plasticizing elemental sulfur with a mixture comprising 3-(2-mercaptoethyl)cyclohexanethiol and 4-(2-mercaptoethyl)cyclohexanethiol and thereafter admixing with the resulting plasticized sulfur diatomite and chlorinated biphenyl.

References Cited UNITED STATES PATENTS 1,761,740 6/1930 Nordlander 106-70 2,093,752 9/1937 Dueoker 10670 2,142,145 l/1939 Patrick 260609 2,237,625 4/1941 Olin 260-608 2,676,165 4 /1954 Fettes 260-79 2,799,593 7/1957 Seymour 10670 3,038,013 6/1962 Warner 260-608 3,342,620 9/1967 Molinet 106--287 FOREIGN PATENTS 1,373,025 8/ 1964 France.

JULIUS FROME, Primary Examiner.

T. MORRIS, Assistant Examiner.

U.S. Cl. X.R. 

